JPH0643061A - Lifting-type center-of-gravity measuring apparatus - Google Patents

Abstract

PURPOSE:To obtain the position of the center of gravity of a material to be measured based on the weight when the material to be measured is lifted through three load cells and the change in weight when the slant angle is changed. CONSTITUTION:A lower frame 5, which suspends a material to be measured 6 at the lower surface so as to determine the position of the material to measures, is attached to the lower side of an upper frame 1 through load cells 2, 3 and 4. Thus, a main body 8 of a lifting apparatus is constituted. Three lifting support points 9, 9 and 9', which are provided in the upper frame 1, are lifted with a lifting device 11. One point 9' of the lifting support points 9, 9 and 9' is moved along the upper frame 1 with a lifting-support-point moving device 15. Thus, the main body 8 of the lifting device is constituted so that the main body can be inclined and moved. Two inclinometers 16 and 17 are arranged at the main body 8 of the lifting device at a right angle to each other. The above described load cells 2, 3 and 4 and the inclinometers 16 and 17 are connected to a center-of-gravity operating device 19.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lifting type center of gravity measuring device.

[0002]

2. Description of the Related Art In various fields of logistics, especially in fields where shape management is strict, such as nuclear equipment, it is sometimes required to know the center of gravity of the equipment accurately. For example, instrument boards are often located at a relatively high center of gravity, and if the center of gravity position is displayed when shipping such equipment, proper packing, transportation, and installation are performed to improve safety. Can be made.

Conventionally, the center of gravity of such equipment has hardly been measured, and when a center of gravity is requested, it is customary to calculate the center of gravity at the design stage.

[0004]

However, in the above-mentioned conventional method for obtaining the position of the center of gravity by the calculation, it is necessary to measure the weight and shape of each part of the equipment in advance, and the equipment is further calculated based on the obtained weight and shape. The work of calculating the center of gravity when assembled is necessary, and this work is very difficult, and even if it is calculated using a computer, the weight of each part,
Since it is necessary to input each shape, and also the mounting position and shape at the time of assembly, the preparation work for the calculation is difficult and takes a long time. Further, when the shape or material of the device is changed, it is necessary to re-execute the calculation each time, which is a very labor-intensive task.

The present invention has been made in view of the above-mentioned problems of the prior art, and is based on the change in the weight of the load cell when the object to be measured is lifted at three points and the change in the weight of the load cell when the inclination angle is changed. It is an object of the present invention to provide a suspension type center of gravity measuring device capable of easily obtaining the position of the center of gravity of an object to be measured.

[0006]

SUMMARY OF THE INVENTION According to the present invention, a lower frame having a lower surface on which a measured object is positioned and suspended is attached to the lower side of an upper frame via three load cells to form a suspension device main body. A hoisting device configured to hoist three hoisting fulcrums provided on the upper frame is provided, and one of the hoisting fulcrums is moved along the upper frame by a hoisting fulcrum moving device so that the hoisting device main body can be tilted. A suspension type center of gravity measuring device, characterized in that two inclinometers are arranged at right angles to each other in the suspension device main body, and the load cell and the inclinometer are connected to a center of gravity computing device, and the inclinometer. It is characterized in that it is provided with only one inclinometer for detecting the inclination angle in the direction of inclining the suspension device main body by holding the suspension device main body horizontally instead of having two. Lifting type centroid measuring device, it relates to a.

[0007]

According to the first aspect of the invention, the hoisting device main body in which the object to be measured is positioned and attached to the lower frame is hoisted by the hoisting device, and the load detection value indicated by each load cell at that time and two inclinometers are shown. The inclination angle is measured by the gravity center calculation device, and the position of the vertical line passing through the gravity center of the object to be measured is calculated from the load detection value and the inclination angle measured by the gravity center calculation device.

Next, the suspension fulcrum moving device moves one of the suspension fulcrums along the upper frame to incline the suspension device main body at a required angle, and the load detection value indicated by each load cell at this time, The inclination angle indicated by the two inclinometers is again measured by the gravity center calculation device, and the position of the vertical line passing through the gravity center of the object to be measured is calculated from the load detection value and the inclination angle measured by the gravity center calculation device.

The position of the intersection of the vertical line passing through the center of gravity before tilting and the vertical line passing through the center of gravity after tilting is calculated by the center of gravity calculating device, and the object to be measured is not suspended. The center-of-gravity position of the suspension device main body, which has been obtained in advance, is input to the center-of-gravity calculation device in advance, and the true center-of-gravity position is obtained by correcting the position of the intersection at the center-of-gravity position of the suspension device main body.

According to the second aspect of the present invention, since the suspension device main body is held horizontally in advance, the number of inclinometers is
It is possible to use only one for detecting the inclination angle in the direction in which the suspension device body is inclined, and the calculation of the center of gravity becomes simple.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 and 2 show an embodiment of the invention of claim 1, in which an upper frame 1 framed in a triangle is provided, and the upper frame 1 is arranged below each vertex of the triangle. A rectangular lower frame 5 which is attached to the upper frame 1 at three points via the load cells 2, 3, 4 is provided, and an object 6 to be measured is positioned on the lower surface of the lower frame 5 so as to be suspended. The hanging device 7 is attached to form the hanging device body 8. In the illustrated case, the positioning suspending tool 7 is arranged in four places on the lower surface of the lower frame 5 so as to form a rectangle, and one of them 7'is fixed in position and defines the origin of the DUT 6. The other three can be moved along the lower frame 5 so that they can be hung even if the size of the DUT 6 changes.

[0013] Three suspension fulcrums 9 are provided on the upper side in the vicinity of each vertex of the triangle of the upper frame 1, and the suspension fulcrums 9 are attached to the suspension rope 1.
A hoisting device 11 is provided so as to hoist through 0.
For the lifting device 11, various devices such as a crane and a hoist can be used.

Of the three suspension fulcrums 9, one suspension fulcrum 9'can be moved toward and away from the other two suspension fulcrums 9, 9 along the linear guide 12 provided on the upper frame 1. A suspension fulcrum moving device 15 is movably mounted on the suspension fulcrum 9 and is configured to move the one suspension fulcrum 9 ′ via the ball screw 13 and the motor 14.

Further, the upper frame 1 of the hanging device main body 8
On top, two inclinometers 16 which are horizontal and at right angles to each other,
17 is provided so that the inclinations from the horizontal plane in the X and Y directions can be detected. In the figure, 18 is a control panel connected to the load cells 2, 3, 4 and inclinometers 16 and 17, and 19 is connected to the load cells 2, 3, 4 and inclinometers 16 and 17 via the control panel. Is a center-of-gravity calculation device for calculating the center-of-gravity of the DUT 6.

In measuring the center of gravity of the object 6 to be measured,
First, the DUT 6 is positioned and attached to the lower frame 5 via the positioning suspending tool 7. At this time, a corner portion of the DUT 6 on the side attached to the one hanging tool 7'fixed is set as an origin O. Subsequently, the lifting device body 8 to which the DUT 6 is attached is lifted by the lifting device 11, and the load detection values indicated by the load cells 2, 3 and 4 at that time, and the inclination angles indicated by the two inclinometers 16 and 17. Is measured by the gravity center calculation device 19. The position of the vertical line passing through the center of gravity of the object to be measured 6 is calculated by the center of gravity calculating device 19 from the detected load value and the inclination angle measured in this way.

That is, as shown in FIGS. 3 (A) and 3 (B), the inclinometers 16 and 17 were used to measure one corner of the upper portion of the object to be measured 6 which is inclined in the suspended state as the origin O. Inclination angle θ
A horizontal plane π of X ′ and Y ′ passing through the origin O is set from _x and θ _y, and the top surface shape of the object to be measured is projected on the horizontal plane π.

The direction cosines l, m, and n are the horizontal plane π: lx +
Since it can be expressed as my + nz = 0, sin, θ _x = −l sin θ _y = −m l ² + m ² + n ² = 1 and l, m, and n can be obtained.

[0019] A 'point of coordinates _{(x a', y a '} , z a')

[Equation 1] If you solve this

[Equation 2] Becomes

[0020] B 'point of coordinates _{(x b', y b '} , z b')

[Equation 3] If you solve this

[Equation 4] Becomes

A vertical line passing through the center of gravity is GG '(G is a plane π
The upper point). GG'⊥ plane π

When the load measurement values at the origins O, A, and B are L ₁ , L ₂ , and L ₃ , the center of gravity G ′ on the plane π.
(X _g ', y _g ', z _g ') is obtained as follows.

[Equation 5]

Therefore, the straight line GG 'is

[Equation 6] Becomes

Next, the suspension fulcrum moving device 15 moves one of the suspension fulcrums 9 along the upper frame 1 to move the suspension device main body 8 to a desired angle θ _x ′, θ _y ′.
The load detection values L ₁ ′, L ₂ ′, and L ₃ ′ of the load cells 2, 3 and 4 at this time are tilted by the same method as the above equation (6), but the equation (6) ′ is omitted. Then, the coordinates of the center of gravity can be obtained by solving the equations (6) and (6) ′ thus obtained as simultaneous equations.

That is, the position (center of gravity) of the intersection of the vertical line passing through the center of gravity of the object 6 before tilting and the vertical line passing through the center of gravity after tilting is obtained by the above calculation. However, since this intersection is the center of gravity of the weight including the suspending device main body 8 in addition to the object to be measured 6, the position of the center of gravity of only the suspending device main body 8 previously obtained in the state where the object to be measured 6 is not suspended is determined. Is input to the center of gravity computing device 19 in advance, and the true position of the center of gravity is calculated from the mass ratio by correcting the position of the intersection calculated including the suspension device body 8 by the center of gravity of the suspension device body 8. To do.

Therefore, according to the above-mentioned embodiment, the object 6 to be measured is hoisted by the hoisting device body 8 and the load cells 2, 3 and 4 and the inclinometers 16 and 17 at this time are measured, and then the hoisting device body 8 is moved. The center of gravity can be measured only by inclining and performing the same measurement, and the center of gravity of the measured object can be accurately measured in a short time by a simple operation.

FIG. 4 shows an embodiment of the invention of claim 2 in which the object to be measured 6 can be held horizontally by the suspension device body 8 (see FIG. 1). From the Y-axis to the X-axis
It shows a case in which the tilt is made only in the direction of the axis and one inclinometer 16 for detecting the tilt angle θ at this time is provided.

According to this embodiment, the vertical line (x ₁ , y ₁ ) W ₁ passing through the center of gravity is determined from the detected weights of the three load cells 2, 3, 4 when the DUT 6 is horizontal. Can
Further, a vertical line (x ₂ , y _{1 which} does not change) W ₂ passing through the center of gravity when the object to be measured is tilted is obtained, and the height position h ₁ of the intersection of the _two vertical lines W ₁ , W ₂ is , H ₁ = x ₁ cot θ−x ₂ cosec θ (7), and the center of gravity G position is measured from the x ₁ , y ₁ , and h ₁ . At this time, the position of the center of gravity G is corrected by the center of gravity of the suspension device main body 8 which is obtained in advance, as described above.

According to the above embodiment, the inclinometer 16 to be installed
Can be only one, and the calculation of the center of gravity can be simplified.

The present invention is not limited to the above embodiment, but the number of load cells and the number of suspension fulcrums can be changed as long as the coordinates of the object to be measured can be obtained. Needless to say, various changes can be made without departing from the scope of the present invention.

[0031]

According to the invention of claim 1, when the object to be measured is lifted at three points via the load cell, the detected load of each load cell and the tilt angle from the two inclinometers are measured, and the object to be measured is further measured. By measuring the load by the load cell again by changing the tilt angle without changing the origin of the object to be measured, the center of gravity calculation device is used to measure the vertical line passing through the center of gravity before tilting and the vertical line passing through the center of gravity after tilting. Calculate the position of the intersection (center of gravity),
Furthermore, by correcting the center of gravity of the suspension device body,
It is possible to obtain an excellent effect of being able to know the position of the center of gravity of the object to be measured with high accuracy and in a short time by a simple operation.

According to the second aspect of the present invention, by holding the suspension device main body horizontally in advance, only one inclinometer is provided for detecting the inclination angle in the direction of inclining the suspension device main body. And the calculation of the center of gravity can be simplified.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of the invention of claim 1;

FIG. 2 is a plan view of FIG.

3A and 3B are diagrams showing the principle of measuring the center of gravity according to the invention of claim 1;

FIG. 4 is a diagram showing the principle of measuring the center of gravity of the invention of claim 2;

[Explanation of symbols]

 1 Upper frame 2 Load cell 3 Load cell 4 Load cell 5 Lower frame 6 Object to be measured 8 Suspension device body 9 Suspension fulcrum 9'Suspension fulcrum (for movement) 11 Suspension device 15 Suspension fulcrum mover 16 Inclinometer 17 Inclinometer 19 Center of gravity computing device

Claims (2)

[Claims] 1. A suspending device main body is constructed by mounting a lower frame on the lower surface of which an object to be measured is positioned and suspended so as to hang the lower frame through three load cells. A hoisting device for hoisting the three hoisting fulcrums provided is provided, and one of the hoisting fulcrums is moved along the upper frame by a hoisting fulcrum moving device so that the hoisting device main body can be tilted. A lifting type center of gravity measuring device, characterized in that two inclinometers are arranged at right angles to each other and the load cell and the inclinometer are connected to a center of gravity calculating device. 2. The two inclinometers according to claim 1 are replaced with only one for detecting the inclination angle in the direction of inclining the suspension device main body by holding the suspension device main body horizontally. A lifting-type center of gravity measuring device comprising an inclinometer.